1. Field
The present invention relates to an abnormal discharge alarm device, and more particularly to a device capable of generating an abnormal discharge alarm without requiring supply of power.
2. Related Art
A steam trap is applied in a steam system. During operation of the steam system, steam, condensate water, and gas usually exist in a pipeline. Major functions of the steam trap are to (a) prevent the steam from leaking from the pipeline, (b) remove condensate water of the system, and (c) discharge uncondensable gas. If the steam trap used is not suitable for the steam system or is in abnormal operation, serious consequences such as water hammer, ineffective heat transfer, steam leakage and system corrosion might occur.
After the steam trap is installed in the steam system, the steam trap discharges the condensate water or uncondensable gas with a valve at a suitable time according to a state of the system and prevents undesired steam leakage. Relatively frequent failures of the steam trap include: (a) valve closure failure after drainage, (b) drainage failure due to valve blockage, and (c) steam leakage.
In order to know whether the steam trap operates normally in advance, persons in this art have proposed failure diagnosis technologies, such as UK Patent Application No. GB2457924, published on Sep. 2, 2009, entitled “Steam Trap Monitoring”, and U.S. Pat. No. 6,644,131, issued on Nov. 11, 2003, entitled “Steam Trap Instrument Module”.
In the former one, a temperature or pressure difference of the steam trap is measured, and failure diagnosis is performed according to the temperature or pressure difference, so as to predict a failure that might occur to the steam trap. In the latter one, a ball float steam trap is disclosed, which includes a pressure sensor, a temperature sensor and an eddy current displacement sensor, and the steam trap is diagnosed using signals returned by the sensors.
Although a current state of the steam trap can be sensed and diagnosis can thus be performed on the steam trap in the prior art, in practical factory applications, due to cost considerations, a maintainer seldom replaces the steam trap according to a prediction that a failure might occur to the steam trap, but usually replaces a failed steam trap when an anomaly occurs to the steam trap. In addition, if it is desired to continuously monitor the state of the steam trap, circuit wiring needs to be provided at all portions in the whole steam system that are arranged with steam traps, and the electric power required for continuous monitoring does not meet the requirements of environmental protection, energy saving, and carbon reduction.